Pop star Bjork has disappointed fans by cancelling her appearance at an Australian music festival due to swollen vocal chords. The It's Oh So Quiet singer was due to perform at Sydney's Big Day Out event on Friday (25Jan08), but has been ordered by medical staff to rest her voice to avoid inflicting any further damage. Bjork's inability to perform has also left organisers unable to find a last-minute replacement for her slot, the penultimate one on the main stage. Other artists on the bill, including Rage Against The MAChine, have been asked to expand their sets as a result.